Science

Conchi Merino: "Social media has portrayed the capybara as a cute pet, and it's not."

Biological Coordinator of the CosmoCaixa Flooded Forest

Science
23/01/2026
7 min

BarcelonaFor fourteen years, Conchi Merino has risen early to care for 5,435 animals of 170 species—and countless ants!—the inhabitants of the CosmoCaixa Flooded Forest, a space that recreates the habitat of the Amazon rainforest, threatened by agricultural, livestock, and mining operations. The guest of honor is Nut the capybara, a giant rodent that inspires passion among the 45 school groups that visit this jungle every day. It is likely that the capybara rivals Snowflake the Great Kiskadee and Ulysses the orca as one of Catalonia's most iconic animals.

The Amazon is home to 10% of the world's animal species and up to 20% of those that live in freshwater.

— The Amazon is the lungs of the world, and every year it loses hectares of primary rainforest that never recover. We must become aware that it is a very delicate and very important ecosystem. Here we recreate an area of ​​the flooded forest in Brazil called Santarém. When it rains heavily, the rivers overflow, and the animals spread out and can live everywhere. When the water level drops, they are left in puddles, with hardly any oxygen, feeding on whatever they can find. That's why many of these animals come to the surface and can breathe atmospheric air. We are here at about 28 degrees Celsius and 80% humidity, which allows all these plants and eight species of birds to thrive.

Conchi Merino and one of the five caretakers of CosmoCaixa feeding the fish in the flooded forest.
Preparing food for the animals of the CosmoCaixa Flooded Forest.

And what about underwater?

— There are more than 50 species of fish, about 4,500 individuals. They are all river animals; therefore, in the wild they eat seeds, leaves, plants, other fish, birds, and anything else that falls into the river. This is the pacu, which is related to the piranha. This is the catfish. The most common is the GeophagusWe have around 3,000 individuals, because they breed a lot, and they are called that because they eat from the ground.

That enormous beast is the pirarucu, isn't it?

— It's the largest freshwater fish in the world and lives in the river basins of South America. These arrived from a farm in Peru in 2016, measuring 20 centimeters, and now they are 1.60 meters long and weigh about 100 kilos. They eat animal protein: carp, river octopus, chicken, hake... And occasionally, the big fish eat the small fish: this is an ecosystem. When we introduce smaller fish, we must put them in places where they can hide. Now it will yawn! The natives say that this brings very good luck.

It's quite unnerving. But the alligator is very still, isn't it?

— Sometimes it floats along with the current, and some children think it's fake! It's a dwarf caiman, one of the smallest crocodiles we have, because it's the only one we can keep in the tank. Now it eats a quail every two weeks because it was a bit too big; it doesn't move around much. Look at the manta ray! [A school of manta rays swims by.] You have to be careful with this one when you go in to clean the tank because it's very observant and has two stingers hidden in its tail that, if it gets scared or you step on it, it raises and they're venomous.

A herd from the flooded forest of CosmoCaixa.
Feeding the fish of the flooded forest.

There are five thousand animals in the forest, but the star is undoubtedly the capybara. Why all the fuss? It's just a rodent!

— Social media has made it seem like a super cute and affectionate animal, like a pet, but it's not; it's a wild animal. It's a herbivore, it's calm, it lives in a pack, but it's not a pet. It needs a lot of space. It spends half its time in the water and the other half sleeping or eating—endive, carrots, apples, peppers, chicory, and pellets—and it likes to crawl through the mud. Because it has fur and is a mammal, people like it much more than reptiles or amphibians... and I didn't know so many people were afraid of birds! Children come all excited to see the capybara, they start shouting, they sing it a song they find online, and the animal gets scared and hides.

Is there a danger that someone might want one at home?

— Not at the moment, and importing them wouldn't be easy either. But you never know: there are many feral monk parakeets in Madrid now, and here in Barcelona we have Argentine parrots that have become established. And that's a problem because these animals displace the native wildlife.

What does a capybara look like?

— This is the third one we've had. Tinka was more affectionate; Nut is shy. She arrived when she was two and is now four. The zoo in Holland warned us that she's a bit skittish. Since they usually live with other animals and we can only have one here, we're her pack: we keep her company and play with her. At 11:00 a.m., we have half an hour of socialization with a keeper; at 1:00 p.m., we train her so she's used to being touched, examined, and even given injections without it being traumatic for her; and at 6:00 p.m., it's time for playtime. She grabs a branch and goes up and down it.

A caretaker of the flooded forest with Nut the capybara.
Nut the capybara in the flooded forest.

The smallest animals they have are ants.

— We have a hotbed of... AttaThese are leafcutter ants. They don't actually eat leaves; they eat the fungus they cultivate from the paste they make with the leaves and their saliva. Sometimes we put flowers or apples on the surface for them. This helps us explain the different types of ants: there's the queen—without whom the anthill ceases to function and dies—there are the workers—who carry the leaves—there are workers who work in the waste disposal area and the cemetery—they carry the dead to a specific part of the anthill—and there are the soldiers—who manage the anthill when it becomes blocked. This colony is nineteen years old, which is a long time under human care. In nature, the queen would lay eggs from which another queen and several winged soldiers would hatch to create a new colony elsewhere.

She has a tarantula. How should she care for it?

— This species is called Nhandu tripepiiFor us, she's Pepi. She's very calm and can stay still all day. She eats every Thursday, if she wants. We offer her food with tongs so the forest ants don't bother her, because if too many came, they might eat her.

What? But the tarantula is terrifying!

— Everyone has a strong aversion to spiders, but a tarantula only has enough venom to kill a lizard or a small mouse. If it bites you and its chelicerae, which are like two cat-like claws in its mouth, pierce your skin, it can cause an infection, but it can't actually kill you unless you're allergic to the venom. People think that the bigger and hairier the spider, the more dangerous it is. That's not actually the case: Black Widow, which lives south of Valencia, does have the ability to kill a person and is very small and not hairy.

Poison dart frogs, so exotic and tiny, are also poisonous.

— Although they are hardly toxic in captivity because they don't eat the beetle that allows them to synthesize the poison, they have the colors that signify danger in nature: yellow with blue, as well as orange or red. When animals see these colors, they know they are poisonous and don't eat them. Some animals mimic these patterns to avoid being eaten, such as the MicrurusThe coral snake, which is very poisonous, and the false coral snake, which is not poisonous but imitates its colors.

Snakes that are difficult to spot live among the frogs.

— They are a type of arboreal boa that blends into their natural surroundings. The two males came from the Vigo Zoo: their names are Vigo and Mortensen. We share surplus animals among our institutions; we don't buy or sell them. Neither anacondas, nor boa constrictors, nor arboreal boas lay eggs; they are ovoviviparous. The young develop inside the mother, and when the time comes, they appear to be alive.

How do you take care of an anaconda? It's like an ox!

— Our facility is unique because we always keep the animals inside; we don't move them around. The anaconda is very calm, so two of us go in: one to clean and one to watch over the animal. If it gets too close, we gently nudge it to pick up.

What can eat you, is it a myth?

— It's a myth. They do eat very large animals. We give her a 1.5-kilo rabbit every twenty days. This one was born in 2018 and weighs about 42 kilos; she still has a lot of growing to do, and they grow very quickly. Snakes never stop growing. An anaconda can reach 90 or 100 kilos and, in captivity, can grow to 6 meters; in the wild, they've been found to be 9 meters long.

Isn't it dangerous?

— Look, it's a predator. If it gets scared and bites you... the problem is that it grabs you, wraps itself around you, and squeezes. It might hurt, yes, you could have an accident, but that's the same with any animal. They're wild and dangerous, but they get used to the way you move around the enclosure, and we haven't had any problems.

A close-up of a snake in the flooded forest of CosmoCaixa.
A turtle in the flooded forest.

Are you sometimes afraid?

— This profession must be your passion; you can't be afraid, you must have respect for animals. You have to know the animal and always work in the safest way possible: with a dangerous animal, we always work with a partner, we always carry the walkieWhen someone puts on the diving suit to clean the tank, there's always another guard...

Animals in captivity...

— We prefer to say "under human care". Captivity It's a word with very negative connotations; it's degrading. We don't keep animals on a whim: we're in a place where we uphold the laws of nature; every animal has something important to say. Nor do we exploit the environment; we have animals that can reproduce in captivity and adapt to living under human care. We follow an animal welfare plan: we have strict space requirements and replicate the same conditions the animals have in their natural habitat so they can do everything they do, just as they do in nature.

Can these animals be loved?

— They're not your dog or your cat, but of course you grow fond of them, because you work with them every day, you take care of them. With reptiles it's more difficult, but the birds and mammals know you, they come to greet you when you arrive, they come to ask for food in the kitchen, they know the caretakers. When they die, you feel bad.

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